Triple Chocolate Mousse Cake

Last week it was my birthday and I had the opportunity to celebrate it three times with my family and friends: once on the actual day and then twice more on the weekend. With all of these celebrations I was able to make not just one, but two cakes for the occasion. Many people, when hearing that I was baking my own birthday cake, asked me if I wouldn't rather someone make a cake for me. Those people clearly don't know me well because obviously baking cake is one of my favorite things to do and being able to bake my own is like a gift to myself. Luckily that question came only from acquaintances and not close friends...they know me better than that.

The funny thing about this cake in particular is that it is definitely not a "me" cake; I'm a cheesecake lover through and through. I don't really love mousse cakes, in fact I never order them in restaurants, and I'm more of a fruit lover than chocolate. So why, one may ask, did I choose to make this cake for my birthday. Well the answer is simple really: I saw this recipe months ago and very badly wanted to try it out. It was different than most cakes I make because it a) wasn't a cheesecake b) was a layered cake c) required a new technique I had never tried. All of these factors, and the fact that it came from my favorite food blog Annie's Eats, made me eager to make it. Originally I was going to make it for my grandmother's birthday, back in the beginning of February, but my mother advised me against it and we ended up making a traditional napoleon cake instead. Then I thought to myself that the next birthday coming up is my cousin's, all the way in May, and I knew she would want a cheesecake. So really that only left me one choice: make it for my own birthday.

Considering how long I had this recipe bookmarked there was a lot of build-up and anticipation in my mind. Even though I really wanted to try my hand at a mousse cake, ultimately I wasn't sure if I would actually like how it tasted; I just wanted the experience so badly! Well not only did the process go smoothly, but it tasted fantastic! The mousse was silky smooth and produced an effect of all three layers simultaneously blending together and melting in your mouth.

At first I was anxious to serve it to my family because we have quite a few "non-mousse-lovers" like me, but I think we have all been converted. Everyone at the table loved it, both for the taste and the texture, and I was shocked when my grandfather and dad each took a second piece. My only one criticism, based on my own personal preferences, is that I wish I had used a slightly less bitter chocolate such as a 60% instead of 72%. When I expressed this most of my family disagreed but I wouldn't have minded a little more sweetness, especially in the very bottom layer of the chocolate flourless cake. 

This mousse has definitely opened the door to a whole new world of cakes for me to make. Cheesecakes still stand as my number one favorite and I will always order that over a mousse cake any day of the week, but it's nice to have variety sometimes and know that I am capable of more.

Triple Chocolate Mousse Cake

For the bottom layer:

• 3/4 cup (6 tbsp) unsalted butter, cut into pieces
• 7 oz (200 g) dark chocolate, cut into pieces
• 3/4 tsp instant espresso powder
• 1 tsp vanilla
• 4 large eggs, separated
• 1/4 tsp salt
• 1/3 cup light brown sugar, packed

1. Combine the butter, chocolate, and espresso powder in a large heatproof bowl set over simmering water. Stir occasionally until completely melted and smooth. Set aside to cool for five minutes, then whisk in the vanilla and egg yolks until evenly incorporated.
2. Beat the salt and egg whites together on medium speed until foamy, about 30 seconds.
3. Crumble half of the brown sugar into the mixture and beat until incorporated, about 15 seconds. Repeat with the remaining brown sugar and then increase the speed to high and beat until stiff peaks form, about one more minute.
4. Using a whisk, mix 1/3 of the egg whites into the chocolate mixture to lighten it. Gently fold in the remaining egg whites with a rubber spatula until no streaks remain.
5. Pour the batter into a 9" springform pan with only the bottom greased and bake for 14-18 minutes at 325 degrees Fahrenheit, or until the cake is firm around the edges but the center is still soft and has just set. 
6. Remove from the oven and cool completely in the pan. If not making the second layer right away cover with plastic wrap and store in the refrigerator until ready to use.

For the middle layer:

• 2 tbsp cocoa powder
• 5 tbsp hot water
• 7 oz (200 g) dark chocolate, cut into pieces
• 1 1/2 cups heavy cream
• 1 tbsp sugar
• 1/4 tsp salt

1. Whisk together the cocoa powder and hot water in a small bowl and set aside.
2. Melt the chocolate in a heatproof bowl set over simmering water, stirring occasionally until smooth, then remove from the heat and let cool slightly.
3. Meanwhile, beat the cream, sugar, and salt on medium speed until it starts to thicken, about 30 seconds. Increase the speed to high and continue to beat until soft peaks form, about 30-60 seconds.
4. Beat in the cocoa water mixture until smooth. Once incorporated, whisk 1/3 of the whipped cream into the melted chocolate to lighten it. Gently fold in the remaining whipped cream with a rubber spatula until no streaks remain.
5. Pour the mousse into the springform pan over the cooled cake and tap gently on the counter a couple of times to remove air bubbles. Gently smooth the top with a spatula and wipe the inside edge to remove any drips. Refrigerate for at least 15 minutes while preparing the top layer.

For the top layer:

• 3/4 tsp powdered gelatin
• 1 tbsp water
• 6 oz (170 g) white chocolate, cut into pieces
• 1 1/2 cups heavy cream

1. In a small bowl, sprinkle the gelatin over the water and let stand for 5 minutes to soften.
2. Bring 1/2 cup of the cream to a boil in a small saucepan. Remove from the heat then add the gelatin mixture and stir until dissolved. 
3. Pour the hot cream over the white chocolate pieces in a medium bowl and whisk until the mixture is smooth. Set aside to cool to room temperature.
4. Meanwhile, beat the remaining cup of cream on medium speed until it starts to thicken, about 30 seconds. Increase the speed to high and continue to beat until soft peaks form, about 30-60 seconds.
5. Whisk 1/3 of the whipped cream into the melted chocolate to lighten it. Gently fold in the remaining whipped cream with a rubber spatula until no streaks remain.
6. Spoon the white chocolate mousse into the pan over the middle layer and smooth with the back of the spoon or an offset spatula. Refrigerate the cake for at least 2 1/2 hours so that it can properly set.